Acute bleeding of oesophageal varices is commonly treated by use of a tamponade tube, such as the Sengstaken-Blakemore tube which was first introduced in 1950, which tube restricts the flow of blood through the vessel, thereby assisting blood coagulation by natural mechanisms. One study has indicated that it will provide initial control of bleeding in over 80% of patients. However, in over 60% of these patients rebleeding will occur when the tube is withdrawn. In the patients who rebleed, there is a 60% rate of mortality.
A number of methods of further treatment are available once bleeding has been arrested. Injection of the varices with a sclerosing agent is feasible only with variceal observation e.g. by an endoscope unobscured by bleeding. Mortalities of around 50% have been found with emergency portasystemic shunting or with gastric or oesophageal surgery. There is a high incidence of rebleeding associated with the use of vasopressin. Thus, none of the methods so far proposed is associated with a high rate of success.
The application of electrical current to induce thrombosis was employed by Lutz in 1951; see Circulation 1951; 3:339-351. Sawyer has demonstrated that passage of current across a normal blood vessel precipitates a thrombus only at the anode; See Amer.J.Physiol. 1960; 198:1006-1010.